1. Field of the Invention
The invention relates to integrated circuits, and more particularly to radiofrequency integrated circuits intended to operate at frequencies greater than or equal to 1 GHz.
2. Description of the Related Art
At the present time, radiofrequency integrated circuits incorporate, within the same substrate, various separate, analog or digital, functional blocks such as, for example, LNAs (low-noise amplifiers), local oscillators, power amplifiers, digital demodulators or even phase-locked loops.
However, the production of integrated circuits is constrained by the need to equip them with electrostatic discharge protection means that protect them from the electrostatic discharges that could damage the electronic components of the integrated circuit.
Conventionally, these electrostatic discharge protection means comprise, in addition to the diodes and conventional protection circuits better known as clamps, several discharge (or metallization) rails respectively connected to the various functional blocks and forming a ground reference for the electrostatic discharges. To ensure continuous electrical continuity between these various discharge rails, provision is made in particular to place back-to-back diodes between the said rails.
However, such a construction induces coupling capacitances between the discharge rails, and consequently potential noise transmission between these rails.
Now, the transmission of noise may hamper, in particular in the radio frequency field, certain particularly sensitive functional blocks such as low-noise amplifiers.
Accordingly, there exists a need for overcoming the disadvantages of the prior art as discussed above.